Plant and process for the production of oil from oil shale and the like



oct. 16, 1962 R M ons 3,058,903

PLANT AND PROCESS 'Fo THE PRODUCTION oF OIL FROM OIL SHALE AND THE LIKE Filed June 15, 1959 'posite oil having a pour point Unite States Patent patented oct. ie, rss2 3,058,903 PLANT AND PROCESS FOR THE PRDUCTlON OF OlL BRGM OL SHASLE AND Tim LIKE Russell M. tis, Pasadena, Calif., assigner to The (lil Shale Corporation, Beverly Hills, Calif., a corporation of Nevada Filed .lune 15, 1959, Ser. No. 820,312 Claims. (Cl. w8- 11) This invention relates generally to the production of oil from solid carbonaceous material, and more particularly relates to the production of cracked oil from oil shale, tar sands, and the like.

The production of an oil which is pipeline at low temperatures, c g. 60 F. or lower, to refinery centers, is generally preferred. In order to achieve this desirable end, the oil obtained directly from the pyrolysis or stripping of carbonaceous materials such as oil shale, tar sands, or the like, must be further proc* essed. By pyrolysis I mean the destructive distillation of the carbonaceous material, and by stripping, I mean distillation generally, whether it be destructive or nondestructive in nature. Preferably, only the heavy portion of the oil vapors and gases, obtained directly from the stripping, is cracked. The cracking of the light ends will produce a large amount of noncondensables; avoiding such cracking substantially reduces the loss of valuable oil which would otherwise be lost in the form of such noncondensables.

The heavy portion of the oil, when cracked (i.e. converted from high-boiling high-molecular weight compounds to a series of low-boiling lower-molecular weight compounds) and added to the light ends of the oil vapors and gases resulting from pyrolysis or stripping, which are not cracked, results in the production of a composite oil of extremely low pour point, the pour point being a good measure of the minimum temperature at which the composite oil is pumpable. It is desirable to produce a cornof between 30 and 60 Production of such a composite oil from oil shale and the like usually entails heavy expenditure in processing equipment such as dust-control equipment, condensation, and cracking equipment in addition to the equipment for retorting. Possibly the main drawback in the commercial production of oil from oil shale is the cost of production of the oil, of which such capital investment in the plant is a substantial factor.

Bearing in mind the foregoing facts, it is a major object of the present invention to provide a plant and process for the production of an oil of low pour point from oil shale, tar sands, and the like wherein the amount of process equipment required is very substantially reduced.

Another major object of the present invention is to provide a plant and process for the production of undiluted low-temperature pumpable oil from oil shale and the like wherein the usual dust-control equipment, con* densing equipment, and special cracking equipment is eliminated, thereby substantially reducing the initial capital investment, and simplifying the process.

A further object of the present invention is to provide a process for the production of a low temperature pumpable oil wherein the heavy ends of pyrolyzed oil vapors and gases are condensed at a particular predetermined temperature by contact with cooler oil shale, these heavy ends then being cracked during the pyrolysis of additional oil shale to produce a mixture of light uncracked and cracked oils which are separable from the pyrolyzed heavy ends by the condensation of the light oils.

Still another object of the present invention is to provide an improved plant and process for the production of undiluted light oil from oil shale wherein the heavy ends of oil vapors and gases resulting from pyrolysis are conpumpable through a densed in the presence of fresh oil shale thereby adding the heat of condensation to the oil shale during the preheating of said oil shale, the oil shale preheating and the condensing of the heavy ends being accomplished in the same piece of equipment, the heavy ends then being recirculated back to the pyrolysis Zone for cracking, the crack-ing and the pyrolysis being accomplished in the same piece of equipment.

These and other objects of the present invention will become more clearly understood by referring to the following detailed description of my invention, and to the accompanying FIGURE, which is a schematic representation of a plant for the production of oil according to one preferred embodiment of my invention. For simplicity, in the following description of my invention, oil shale is considered as the material from which oil is produced by pyrolysis, but the same plant and the same process may be employed for production of oil from other materials, such as tar sands and the like, by stripping involving nondestructive distillation as well as by pyrolysis.

In general, my invention comprises preheating oil shale or the like by means of hot solid bodies in a first zone, the preheated oil shale then being pyrolyzed by means of hotter solid bodies in a second Zone. The eilluent oil vapors and gases resulting from pyrolysis are then sent to the first zone, for contact with a mixture of additional fresh oil shale yand partially cooled solid bodies, which results in the condensation of heavy ends of said effluent oil vapors and gases on said oil shale. The light ends are not condensed in the preheater and pass therefrom, as vapor, to be condensed at a later time or sent to further processing.

The condensed heavy ends are sent, with the oil shale, to the pyrolysis zone where they are cracked by reheated solid bodies. At the same time, the solid bodies cause pyrolysis of the freshly preheated oil shale, and the crushing thereof to render the pyrolysis more eicient.

The pyrolyzed and cracked vapors are then sent to the preheating zone. The heavy ends of the vapors are condensed by the oil shale in the preheating zone, and the lighter oil product, both cracked and noncracked, pass out as vapor. The resulting oil product has a low pour point, and is suitable for pumping at temperatures in the neighborhood of 30' to 60 F.

Referring now particularly to the FGURE, fresh oil shale, in hopper l2, is introduced into a rotating drum 'l via line 13. T-he rotating drum also has an inlet for substantially hotter solid heat-carrying bodies, and an inlet for vapors which have resulted from previous pyrolysis and cracking, both the solid bodies and vapors corning from another rotating drum ll via conduits 14 and 22 respectively.

The solid bodies are preferably of approximately the same, or larger, average size as the fresh oil shale. Both drums lil and 1l have screen means for the purpose of separating the oil shale or oil shale residues from the solid bodies. By way of example, the rotatable drum shown and described in Aspegren Patent No. 2,872,386 may be employed, with some modifications. While parallel flow of solid materials is preferred, as shown, counterow of solid materials may also be employed.

The hot heat-carrying bodies or balls are generally spherical in shape and are -made of steel or ceramic material. These balls transfer a substantial portion of their heat to the fresh oil shale to thereby heat the oil shale. Also, the hotter vapors resulting from pyrolysis and cracking in the drum 11 are introduced into the ball and oil shale mixture at a particular point in the drum lll, for example at points A, B, or C, the particular point or section chosen depending on desired operating and condensation characteristics.

The oil shale is preferably preheated to a temperature in the range of 400 to 600 F. Above approximately 600 F., pyrolysis commences, and vapors (containing some heavy ends) would escape from the drum if pyrolysis should Voccur therein. To avoid this, the temperature within the drum is preferably kept below approximately 600 F. Thus, those vapors produced during pyrolysis and cracking in the reactor zone 11 (to be described), which have a boiling point higher than 600 F. (the heavy ends), condense on the oil shale in the preheat drum 10 while those gases and vapors having a boiling point below 600I F. (the light ends), do not condense but leave t-he drum via overhead conduit 23 to be sent Yto a condensing stage (not shown) or to other processing. The vapors do not condense on the balls to any appreciable extent -because the temperature of the oil shale is lower than the temperature of the incoming balls, as will be explained Yin greater detail.

'It will be noted that condensing equipment is eliminated by the relatively simple expedient of utilizing the oil shale in the preheater drum 10 as the condenser. Also, the heat of condensation of the Vheavy oil vapors and lgasesis transferred directly to the oil shale, making the condensation process ellicient from the point of view of heat transfer and usage of heat. It should also be noted that condensation of the heavy oil vapors and gases is more ecient in a rotating drum because the cool surface of the lfresh oil shale is continuously presented to the incoming gaseous stream. Also, the condensation process is extremely eicient because the heat-carrying bodies crush the incoming oil shale, thus continually pro- ,ducing new cooling surface for the condensation process.

After the condensation of the heavy oil vapors it is sent along with the preheated oil shale, via conduit 15', to the reactor drum 11. 'I'he oil shale and the liquid condensate deposited thereon Vare separated from the balls by a Screen (not shown) in the drum 10*inasmuch as the oil shale, due to the crushing action of the balls, and/or initial smaller inlet size, is substantially smaller than the balls. Other suitable separating means may also be used, such as Trommel means.

The balls travel, via line 16, to the ball heating zone 30 for reheating to a temperature of 1000 to l400 F., as will be described, and thence are recirculated into the reactor drum 11, via conduit 18. V

The condensate, preheated oil shale, and heated balls enter the rotating drum 111, which is of a type similar to drum 10,`and are thoroughly intermixed therein. The Weight ratio of balls to oil shale preferably ranges be-V tween 1:l and 3:1, depending upon t-he nature of the oil shale being processed, the type of heat-carrying bodies used, and the rate of heat-transfer sought. Pyrolysis of Vthe oil shale results, along with a cracking of the heavy oil condensate.

The average temperature of the eiiuent vapors and Vgases resulting `from pyrolysis and cracking is 750 F.

to 950 F., while the residence time of the oil shale and balls in the reactor drum 11 ranges preferably between one to ten minutes. These eluent vapors and gases are then sent to the preheater 10 via conduit 22, for condensation of the heavier oil vapors.

Any dust which tends to leave the pyrolysis drum 11 with the evolved vapors and gases will pass into the preheat `drum 10. Most of the dust is caught in the drum 10 by the oil shale which, at the stage, has not yet been reduced to dusty powder but, instead, is of a character such that it tends to hold dust which contacts it. Thus, the use of the preheat drum, in the manner described, largely eliminates the problem of dust.

The balls are cooled in the reactor drum 11, to a temperature of between 850 and 1050 F. They are then sent, via line 14, to the preheater 10, for the preheating of fresh incoming oil shale. The balls meet the cooler oil shale and are intermixed therewith in the rotating drum 10. The oil vapors and gases are introduced into `the drum 10, via line 22, asV previously described.

' shale may be F. or so, the amount of condensation decreases.

The heavy ends in the 750 to 950 F. oil vapors ini\ tially begin condensing on the cool oil shale, in preference to the much hotter 850 to l050 F. balls. At all l0-v cations in the drum 10, even near the outlet end where the balls have a temperature of about 650 F. to 750 F., the oil vapors boiling above 600 F. continue to condense upon the oil shale rather than upon the balls since the temperature of the oil shale preferably does not rise about 600 F. in the drum. Any oil condensation that may take place .on the balls is only temporary because it is found that the oi1.shale scrubs the condensed droplets of oil from the balls. In this regard, the oil shale is Vhighly adsorbent relative to the balls, and any condensed oil onthe balls is thus readily transferred to' the oil shale.

The solidV residue of theV pyrolyzed oil shale in the reactor drum 11 contains xed combustible carbon, and is herein referred to as shale coke. The shale coke is sent to a combustion unit or zone 17 via line 20, and burned, for example, in a uidized bed, in the presence of oxygen or air entering v ia line 3S. The products of combustion are extremely hot, and pass upwardly, via conduit 34, to transfer their heat to the balls for the re-` heating in a ball-heating zone or tower 30.

Y The temperature of the products of combustion en'- tering the zone 30 areY lowered, if necessary, by means of the introduction of a steam-producing apparatus or boiler 32 in theV combustion zone 17. The steam pro-V duced may be used for power generation purposes. Ash and combusted gases leave theV top of the zone 30, via line 36. VWhile one type of combustion unit is shown and described, other units may also be employed with success.

A further simplification of the above-described plant for theV production of oil from oil shale can be made by conducting the vapors Afrom the pyrolysis drum 11 out through the conduit 14 with the balls. In this manner, one not only avoids an additional conduit but gains further cracking of the vapors during the transit of the lvapors from the one drum to the other.

A specific example of the process is set forth below:

. YOne ton of Coloradooil shale enters the rotating preheat drum 10 at a temperature of 50V F. via line 13. The oil shale contains kerogen from which, by IFischer assay, approximately 25 gallons of oil'per ton of oil produced. The oil shale has been previously crushed to an average mesh size of one-half inch.

1.5 tons of inch ceramic balls enter the drum 10, at a temperature of 950 F., coming from the reactor 11. 'I'he balls and oil shale are intimately intermixed in the drum, and oil vapors and gases are then introduced, via line 22 and line B, into the ball and oil shale mixture. These oil vapors and gases comprise a mixture of oil vapors and gases, produced by both pyrolysis and cracking, and come hom the reactor drum 11.

The oil vapors and gases contain heavy components having boiling points above 600 F. These heavy components commence condensing on the cooler oil shale, and as the temperature of the oil shale increases to 600 Any slight condensation on the balls (which, near the outlet end, have a temperature of about 650 to 750 F.) is removed by the intermixing of the more adsorbent oil shale With the balls, as previously described.

The cooled balls are transferred to the ball-heating Vzone 30, via -line 16, for heating to l300 F. by means of the combustion of shale coke, in combustion zone 17 The oil shale, plus the liquid condensate thereon, both at about 600 F., are sent, via conduit 15, to the rotating reactor drum 11. The balls, now reheated in zone 30, to l300 F. are also sent to drum 11, kvia line 18.

The balls, oil shale, and condensed oil, are intimately intertnixed in the rotating drum 11, the residence time of the solid materials being about ve minutes. As a lresult of theintimate contact of the yoil shale with the hot balls, the shale is heated to a temperature of 850 F. to 875 F., producing pyrolysis of the oil shale. By contact with the hot balls and shale, the condensed oil entering the drum 11 is cracked. The vapor and gases produced by the pyrolysis and cracking pass from the reactor drum 11 via line 22 at a temperature of about 850 to 875 F.

The balls, leaving the drum 11, via line 14, have an exit temperature of about 950 F. to 975 F. The balls enter the preheat drum, and are intermixed with the fresh oil shale. The eiiluent vapors, from the drum 11, are then introduced along line B, and the heavy oils condensed therefrom on the oil shale, as described.

The product vapors, leaving along line 23, are then preferably condensed. The average pour point of the condensed oil is about 40 F. while the total yield of oil is about pounds per ton of oil shale, or about 80 percent of the total oil collectible.

While the prefered embodiment of my invention has been shown and described, it will be understood that changes and modifications may be made that lie within the skill of the art. Hence, I intend to be limited only by the appended claims.

I claim:

1. A process for the production of oil from solid carbonaceous material which comprises pyrolyzing preheated solid carbonaceous material in a reactor zone to thereby produce efuent vapor containing light and heavy oil vapors and gases; condensing the heavy oil vapors and gases from said eluent vapor on solid carbonaceous material in a preheating zone, the light oil vapors and gases being noncondensed and thereby separated from the heavy oil vapors and gases, the fresh solid carbonaceous material being further heated during the preheating in said preheating zone by heat transferred from said oil vapors and gases and by the heat of condensation of said condensing heavy oil vapors and gases; passing said condensed heavy oil vapors and gases together with said preheated solid carbonaceous material into said reactor zone for the cracking of said heavy oil and the simultaneous pyrolysis of said preheated solid carbonaceous material to thereby evolve additional eiiiuent vapor from said pyrolysis as well as light noncondensable oil vapors and gases from said cracking.

2. The process according to claim 1 wherein the carbonaceous material is oil shale.

3. The process according to claim 1 wherein the heat for said pyrolysis and for said preheating is furnished by solid heat-carrying bodies.

4. A process for the production of oil from oil shale, which comprises: heating heat-carrying bodies in a heating zone; passing said heat-carrying bodies from said heating zone to a reactor Zone and thence to a lower-temperatured preheating zone and back to said heating zone; pyrolyzing preheated oil shale in said reactor zone, by heat transferred from said heat-carrying bodies, to thereby produce effluent vapor containing light and heavy oil vapors and gases; condensing the heavy oil vapors and gases from said efuent vapor stream on oil shale in said preheating zone, the light oil vapors and gases being noncondensed and thereby separated from the heavy oil vapors and gases, the fresh oil shale being heated in said preheating zone by admixture with said heat-carrying bodies, by heat transferred from said oil vapors and gases, and by the heat of condensation of said condensing heavy Oil vapors; passing said heavy condensed oil, together with said preheated oil shale, into said reactor zone for the cracking of said heavy oil and the simultaneous pyrolysis of said preheated oil shale, to thereby evolve additional effluent vapor as well as light noncondensable oil vapors and gases produced during said cracking.

5. The process of cla-im 4 wherein said heat-carrying solid bodies and said oil vapors and gases produced actor Zone pass, in heat-transfer relationship, reactor zone to said preheating zone.

6. The process of claim 4 wherein the oil shale is preheated to a temperature between 400 F. and 600 F. in said preheater zone.

7. The process of claim 4 wherein the temperature of pyrolysis and cracking varies from between 850 F. and 1050 F.

8. The process of claim 4 wherein shale coke produced during pyrolysis is combusted, and heat in the resulting products of combustion is transferred to the solid heatcarrying bodies prior to their entry into said reactor zone.

9. A process for the production of oil from oil shale, which comprises: preheating fresh oil shale in a preheating zone to a temperature of below 600 F. by admixture thereof with hotter heat-carrying bodies, and with hotter vapors containing both heavy and light ends, said heavy ends being condensed by said fresh oil shale, and said light ends passing off as Vapor; passing said condensed heavy ends, together with said preheated oil shale to a reactor zone; pyrolyzing said preheated oil shale, and cracking said heavy ends, by admiXture of these materials with preheated heat-carrying bodies, the temperature of said pyrolyzed and cracked vapors ranging between 850 F. and 1050 F., said preheating, condensing, pyrolyzing and cracking constituting one cycle; and repeating the cycle by condensing the heavy ends from said hot vapors in said preheating zone, by contact with additional oil shale, those light ends, both cracked and uncracked, having a boiling point below the temperature of said preheated oil shale, not being condensed, and being thereby separated from said heavy ends, the heat of condensation of said heavy ends, as well as the heat of said hotter vapors, being utilized to heat said additional oil shale, the additional oil shale being also heated by admixture with heat-carrying bodies coming from the reactor zone.

10. Apparatus for the production of oil from solid carbonaceous material of a -type from which oil can be produced by heating, which apparatus comprises: a rotatable preheating drum; a rotatable reactor drum; means for introducing said solid carbonaceous material into said preheating drum; means for introducing solid heat-carrying bodies into said preheating drum for admixture with said solid carbonaceous material; means for conducing introducing vapors from said reactor drum and into said preheating drum for partial condensation on said solid carbonaceous material; outlet means from said preheating drum for noncondensed vapors; means for separating said solid carbonaceous material, and condensate thereon, from said heat-carrying bodies; means for reheating said heat-carrying bodies; means for transferring said solid carbonaceous material, and condensate thereon, from the preheating drum, to said reactor drum; means for transferring said reheated heat-carrying bodies from the reheating means to said reactor drum for heating of said solid carbonaceous material and cracking of said liquid condensate to produce effluent vapors; and separate means for recirculating said cooled heat-carrying bodies and said eliiiuent vapors from said reactor drum t0 said preheating rum.

in said refrom said References Cited in the tile of this patent UNTED STATES PATENTS 1,447,297 Day Mar. 6, 1923 2,406,810 Day Sept. 3, 1946 2,471,107 Hemminger May 24, 1949 2,694,037 Johnson et al Nov. 9, 1954 2,872,386 Aspergren Feb. 3, 1959 2,885,338 Evans May 5, 1959 

1. A PROCESS FOR THE PRODUCTION OF OIL FROM SOLID CARBONACEOUS MATERIAL WHICH COMPRISES PYROLYZING PREHEATED SOLID CARBONACEOUS MATERIAL IN A REACTOR ZONE TO THEREBY PRODUCE EFFLUENT VAPOR CONTAINING LIGHT AND HEAVY OIL VARPORS AND GASES; CONDENSING THE HEAVY OIL VAPORS AND GASES FROM SAID EFFLUENT VAPOR ON SOLID CARBONACEOUS MATERIAL IN A PREHEATING ZONE, THE LIGHT OIL VAPORS ANDD GASES BEING NONCONDENSED AND THEREBY SEPARATED FROM THE HEAVY OIL VAPORS AND GASES, THE FRESH SOLID CARBONACEOUS MATERIAL BEING FURTHER HEATED DURING THE PREHEATING IN SAID PREHEATING ZONE BY HEAT TRANSFERRED FROM SAID OIL VAPORS AND GASES AND BY THE HEAT OF CONDENSATION OF SAID CONDENSING HEAVY OIL VAPORS AND GASES; PASSING SAID CONDENSED HEAVY OIL VAPORS AND GASES TOGETHER WITH SAID PREHEATED SOLID CARBONACEOUS MATERIAL INTO SAID REACTOR ZONE FOR THE CRACKING OF SAID HEAVY OIL AND THE SIMULTANEOUS PYROLYSIS OF SAID PREHEATED SOLID CARBONACEOUS MATERIAL TO THEREBY EVOLVE ADDITIONAL EFFLUENT VAPOR FROM SAID PYROLYSIS AS WELL AS LIGHT NONCONDENSABLEE OIL VAPORS AND GASES FROM SAID CRACKING. 